1. Field of the Invention
The invention relates to an apparatus for densifying materials for the production of pellets, logs, or the like. The present invention further relates to a method for densifying coated paper for the production of fuel pellets, logs, or the like.
2. Description of the Related Art
Various densifier apparatus are known in which material is forced through radially extending openings in a die ring by the action of press rollers. In a typical apparatus, two or more press rollers are mounted for rotation inside a die ring. The circumferences of the press rollers roll along the inner circumference of the die ring. The die ring is formed with a number of radially directed openings. Material introduced within the die ring is forced through the openings by the press rollers, thereby forming densified pellets, logs, or the like.
The material to be densified by such apparatus may vary widely in properties such as consistency, particle size, and cohesion. Accordingly, there is a need to regulate the rate at which the material flows into the die ring.
High fuel costs for generating electricity and heating have brought about a need for alternative energy sources. At the same time, ecological concerns have focused on the need to recycle or utilize scrap to the greatest possible extent. Processes for converting scrap material into fuel are, therefore, of great interest.
One type of scrap material available in large quantities is coated paper. Typically, such paper is coated with wax or polyethylene to render the paper impermeable to moisture. While coated paper is highly combustible, paper in sheet form burns rapidly at a rate that is difficult to control. Accordingly, there is a need for a process to convert coated paper waste to a form suitable for use as a fuel source.
It is known to make combustible fuel pellets, fireplace logs, and the like by densifying cellulosic materials such as paper and wood fiber. The materials are first ground or shredded, then a binding agent, such as a wax, is added. The mixture is densified to produce the pellets. Such a method is disadvantageous insofar as it requires the addition of a binding agent. Accordingly, there is a need for such a method in which no additional binding agent is required.